Diameter–basal area ratio as a practical stand density measure for pruned plantations

The ratio of mean tree diameter to stand basal area (D:BA) is a simple and practical index to guide stocking rates in plantations. When plotted on a Reineke style stand density diagram the D:BA ratio implies a size:stocking trend steeper than that measured in naturally self thinning forests of both Eucalyptus delegatensis and Eucalyptus regnans. Eucalypt plantations held at a constant D:BA ratio will therefore become more competitive with age rather than less competitive as is the case with constant stand basal area. Data from eucalypt and pine plantations in Australia and New Zealand are used to demonstrate the utility of this index as a management tool for small-scale non-industrial forest owners.